How to find which file is stacked?

[ubacher]

In the headline of my F&M window it shows 1 file stacked.
How can I find that file?

If I filter with the Files Properties Panel it shows me all Master/Version stacks.

[ubacher]

Something went wrong. I managed to find the stack. (It did not show on the stack panel!)
I could not unstack it.
Tried various things and eventually managed to delete the stack.

(I do not use stacks - this must have been left over when I played with stacks)

[Mario]

To find stacks, use the Filter Panel > File Properties.